rootdir: properly enable zram

* use 512mb
* lz4 as default compression alg

product/ramdisk.mk

@@ -1,6 +1,6 @@
  # Ramdisk
  PRODUCT_COPY_FILES += \
-     $(LOCAL_PATH)/rootdir/enableswap.sh:root/enableswap.sh \
+     $(LOCAL_PATH)/rootdir/fstab.swap:root/fstab.swap \
      $(LOCAL_PATH)/rootdir/factory_init.project.rc:root/factory_init.project.rc \
      $(LOCAL_PATH)/rootdir/factory_init.rc:root/factory_init.rc \
      $(LOCAL_PATH)/rootdir/fstab.mt6735:root/fstab.mt6735 \

rootdir/enableswap.sh

@@ -1,4 +0,0 @@
-#!/bin/sh
-echo 0 > /sys/block/zram0/disksize
-/system/bin/tiny_mkswap /dev/block/zram0
-/system/bin/tiny_swapon /dev/block/zram0

rootdir/fstab.swap

@@ -0,0 +1 @@
+/dev/block/zram0                             none         swap    defaults      zramsize=536870912,zramstreams=3

rootdir/init.mt6735.rc

@@ -66,6 +66,10 @@ on fs
     write /proc/bootprof "INIT:Mount_END"
 
 on post-fs
+    write /sys/block/zram0/comp_algorithm lz4
+    swapon_all /fstab.swap
+    write /proc/sys/vm/page-cluster 0
+
     # Support legacy paths
     symlink /sdcard /storage/sdcard0
 
@@ -923,11 +927,6 @@ service PPLAgent /system/bin/ppl_agent
     user system
     group system cache
 
-service enableswap /system/bin/sh /enableswap.sh
-    class late_start
-    oneshot
-    seclabel u:r:enableswap:s0
-
 service agpsd /system/bin/mtk_agpsd
     class main
     socket agpsd stream 660 gps system